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Breathing new life into old bricks
Making bricks is a very resource- and energy-intensive process.
Meanwhile, when existing brick buildings are demolished, most of the resulting debris, which can contain many thousands of whole bricks, is sent
to a landfill or crushed. Now, a European Union-funded project called
REBRICK developed and demonstrated a new system that automatically
sorts demolition waste, separating out bricks for reuse. Bricks can easily
last for several centuries, but bricks in demolition waste are simply
thrown out or, at best, crushed and used as aggregate material for low
grade applications such as sub-base and road construction.
The REBRICK system, patented by Gamle Mursten, Denmark, automatically cleans concrete and cement from old bricks so they can be
reused in building construction. "By reusing old bricks and transferring
their history and applying their character to new buildings, they become
tangible examples of the potential that is hidden in demolition debris,"
says Claus Nielsen of Gamle Mursten. If successful, the new system could
deliver an annual waste reduction of 24,000 tons in the project's second
year. www.eaci-projects.eu/eco/page/Page.jsp?op=project_detail&prid=2039.
Image courtesy of Fruggo.
Furniture is going green
Roger Bateman (left), senior
lecturer in furniture design, with
student Matt Harding and a piece
of 100% biodegradable furniture.
A student at Sheffield Hallam University, UK, is creating furniture made from a 100%
biodegradable material, which can be composted at the end of its lifespan. Roger Bateman, senior lecturer in furniture design, spent a year working with student Matt Harding on the Biofurniture project, which aims to simplify production of 100% biodegradable furniture. The project, in
collaboration with Netcomposites in nearby Chesterfield, started as a study into whether plantbased material could be used to make furniture components, instead of using petrochemicalbased plastics. The resulting product is made entirely from flax and a natural plastic derived from
maize, and will eventually decompose.
Bateman worked with Netcomposites to exploit a fabric made from flax and the plant-based
polymer PLA. Next, he designed furniture products that use the material as structural, lightweight
panel components to replace less environmentally-friendly, man-made boards, such as MDF or
chipboard. For more information: Roger Bateman, r.bateman@shu.ac.uk, 0114 225-2631,
www.shu.ac.uk.
Throwing out gold? Not anymore thanks to x-ray vision
Powerful x-rays can now be used to rapidly and accurately detect gold in ore samples, thanks to a new technique developed by Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia. Working with Canadian company Mevex, CSIRO conducted a pilot study that shows that gamma-activation analysis (GAA) offers a much
faster, more accurate way to detect gold than traditional chemical analysis methods.
GAA works by scanning mineral samples, typically weighing around half a kilogram, using high-energy
x-rays similar to those used in hospitals. The x-rays activate any gold in the sample, and the activation is
then picked up using a sensitive detector. According to project leader, James Tickner, CSIRO's study showed
that this method is two-to-three times more accurate than the standard industry technique "fire assay," which
requires samples to be heated to 1200°C.
Tickner explains that a gold processing plant may only recover between 65-85% of gold present in mined
rock. Given that a typical plant produces around AUD $1 billion of gold each year, this means hundreds of
millions of dollars' worth of gold is going to waste.
One major benefit of GAA is that it is easily automated, allowing for much quicker analysis of ore samples. It is also more sustainable—no use of heavy metals such as lead is required. It is also very adaptable.
"While most of the work we've done has been based on the gold industry, the technique can be modified for
other valuable commodities such as silver, lead, zinc, copper, and the platinum group metals," says Tickner.
An 8-kg gold nugget.
For more information: James Tickner, 618/8303-8430, james.tickner@csiro.au, www.csiro.au.
ADVANCED MATERIALS & PROCESSES • NOVEMBER-DECEMBER 2013
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